Aurex AD-15/AD-15K

Commentary

An adres unit that can use the Automatic Dynamic Range Expansion System (adres) on a cassette or tape deck.

The adres unit is connected to the input / output terminal of the tape deck and can be used as an encoder and decoder to improve the noise level by 30 dB.

When used in combination with a deck, the input signal levels for encoding and decoding must be matched to the output level of the deck. The AD-15 has a calibration function so that the level can be adjusted.
First, turn ON the calibration switch of the adres unit and record on the tape deck at a level of -3dB for about 10 seconds while setting the function of the unit to Record.
Next, set the unit function to Play, maximize the output level adjustment knob on the tape deck, and play back the recorded calibration signal.
Then, adjust the semi-fixed volume of the CAL-PLAY with a flat-blade screwdriver so that both LEDs of the calibration indicator of the adres unit light up.

This system consists of a variable response circuit (VRA), a level sensor that records control signals to control the VRA, and a weighting network that provides frequency characteristics.

There are 2 kinds of color variations, AD-15 of walkers or rollators for the elderly Ra and AD-15K of BlackCar Ra.

Model Rating

Type	Adres unit
Number of channels	2-Channel (Recording / Playback switching)
Input impedance	50k Ω
Reference input level	150mV
Maximum input level	5V
Reference output level	150mV
Load impedance	10k Ω or more
Calibration signal	1 kHz (150 mV) adres reference level
Frequency characteristic	20 Hz ~ 20 kHz ± 1 dB (at encoding / decoding)
Distortion factor	0.15% (adres reference level, encode / decode)
Input reduced noise	-100dBm or less
Adres effect	Maximum Recording Level : 7 db improvement (1 khz) Noise Level : 17 dB reduction (100 Hz) 20 db reduction (1 khz) 30 db reduction (10 khz) Distortion Factor : 1 / 6 improvement (1 kHz)
Semiconductor used	IC : 11 Transistor : 9 Diode : 13 pcs
Pwer	AC100V 50Hz/60Hz
Power consumption	5W
External dimensions	Width 257x Height 54x Depth 206 mm
Weight	2.1kg